Slot Aggregation and Selective Prioritization for Physical Sidelink Feedback Channel Communications

ABSTRACT

Embodiments are presented herein of apparatuses, systems, baseband processors, and methods for performing vehicle-to-everything sidelink communication. A wireless device receives first control information through a sidelink control channel specifying one or more first time slots for the wireless device to transmit a first acknowledgment message over a sidelink feedback channel. The wireless device transmits second control information through the sidelink control channel specifying one or more second time slots for the wireless device to receive a second acknowledgment message over the sidelink feedback channel. The first and second time slots at least partially overlap, and it is determined whether the first data packet or the second data packet has a higher priority. The acknowledgment message associated with the higher priority data packet is transmitted or received during at least a subset of the overlapping time slots.

FIELD

The present application relates to wireless devices, and moreparticularly to apparatuses, systems, and methods for wireless devicesto perform selective prioritization of sidelink communication invehicle-to-everything (V2X) wireless cellular communications.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. Oneproposed use of wireless communications is in vehicular applications,particularly in V2X (vehicle-to-everything) systems. V2X systems allowfor communication between vehicles (e.g., via communications deviceshoused in or otherwise carried by vehicles), pedestrian UEs (includingUEs carried by other persons such as cyclists, etc.), and other wirelesscommunications devices for various purposes, such as to coordinatetraffic activity, facilitate autonomous driving, and perform collisionavoidance.

V2X communication has the potential to be a source of increasing demandand range of envisioned uses of wireless communication, which maypresent a variety of design and development challenges. Accordingly,improvements in the field in support of such development and design aredesired.

SUMMARY

Embodiments are presented herein of apparatuses, systems, and methodsfor performing vehicle-to-everything (V2X) sidelink wireless cellularcommunications. In some embodiments, a baseband processor is configuredto perform operations, as described herein. For example, the basebandprocessor may be installed within the described wireless device.

In some embodiments, a wireless device receives first controlinformation through a sidelink control channel specifying one or morefirst time slots for the wireless device to transmit a firstacknowledgment message over a sidelink feedback channel. The firstacknowledgment message provides acknowledgment for a first data packetreceived by the wireless device.

In some embodiments, the wireless device transmits second controlinformation through the sidelink control channel specifying one or moresecond time slots for the wireless device to receive a secondacknowledgment message over the sidelink feedback channel. The secondacknowledgment message provides acknowledgment for a second data packettransmitted by the wireless device.

In some embodiments, it is determined that one or more of the first timeslots coincide with one or more of the second time slots. It is thendetermined whether the first data packet or the second data packet has ahigher priority.

Based a determination that the first data packet has the higherpriority, the first acknowledgment message is transmitted during a firstsubset of the first time slots that coincide with one or more of thesecond time slots, and the second acknowledgment message is not receivedduring the first subset of the first time slots.

Alternatively, based on a determination that the second data packet hasthe higher priority, the second acknowledgment message is receivedduring the first subset of the first time slots, and the firstacknowledgment message is not transmitted during the first subset of thefirst time slots.

Note that the techniques described herein may be implemented in and/orused with a number of different types of devices, including but notlimited to, base stations, access points, cellular phones, portablemedia players, tablet computers, wearable devices, and various othercomputing devices.

This Summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present subject matter can be obtainedwhen the following detailed description of various embodiments isconsidered in conjunction with the following drawings, in which:

FIG. 1 illustrates an example vehicle-to-everything (V2X) communicationsystem, according to some embodiments;

FIG. 2 illustrates a base station in communication with a user equipment(UE) device, according to some embodiments:

FIG. 3 is an example block diagram of a UE, according to someembodiments;

FIG. 4 is an example block diagram of a base station, according to someembodiments;

FIGS. 5A-C illustrate resource pools indicating resource allocationsimplementing slot aggregation for sidelink feedback communications,according to some embodiments;

FIGS. 6A-B are resource pools illustrating selective prioritization forsidelink feedback transmission and reception, according to someembodiments;

FIGS. 7A-B are resource pools illustrating resource sharing for sidelinkfeedback transmission and reception, according to some embodiments;

FIGS. 8A-B are resource pools illustrating weighted resource sharingsidelink feedback transmission and reception, according to someembodiments;

FIGS. 9A-B are resource pools illustrating selective prioritization oflong and short format sidelink feedback transmission and reception,according to some embodiments;

FIG. 10 is a flowchart diagram illustrating a method for performingselective prioritization for sidelink feedback transmission andreception, according to some embodiments; and

FIG. 11 is a flowchart diagram illustrating a method for performingselective prioritization for sidelink feedback transmissions and uplinkdata transmissions, according to some embodiments.

While the features described herein may be susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and are herein described indetail. It should be understood, however, that the drawings and detaileddescription thereto are not intended to be limiting to the particularform disclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the subject matter as defined by the appended claims.

DETAILED DESCRIPTION Terms

The following is a glossary of terms used in this disclosure:

Memory Medium—Any of various types of non-transitory memory devices orstorage devices. The term “memory medium” is intended to include aninstallation medium, e.g., a CD-ROM, floppy disks, or tape device; acomputer system memory or random-access memory such as DRAM, DDR RAM,SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash,magnetic media, e.g., a hard drive, or optical storage; registers, orother similar types of memory elements, etc. The memory medium mayinclude other types of non-transitory memory as well or combinationsthereof. In addition, the memory medium may be located in a firstcomputer system in which the programs are executed, or may be located ina second different computer system which connects to the first computersystem over a network, such as the Internet. In the latter instance, thesecond computer system may provide program instructions to the firstcomputer for execution. The term “memory medium” may include two or morememory mediums which may reside in different locations, e.g., indifferent computer systems that are connected over a network. The memorymedium may store program instructions (e.g., embodied as computerprograms) that may be executed by one or more processors.

Programmable Hardware Element—includes various hardware devicescomprising multiple programmable function blocks connected via aprogrammable interconnect. Examples include FPGAs (Field ProgrammableGate Arrays). PLDs (Programmable Logic Devices), FPOAs (FieldProgrammable Object Arrays), and CPLDs (Complex PLDs). The programmablefunction blocks may range from fine grained (combinatorial logic or lookup tables) to coarse grained (arithmetic logic units or processorcores). A programmable hardware element may also be referred to as“reconfigurable logic”.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

User Device—as used herein, may refer generally in the context of V2Xsystems to devices that are associated with mobile actors or trafficparticipants in a V2X system, i.e., mobile (able-to-move) communicationdevices such as vehicles and pedestrian user equipment (PUE) devices, asopposed to infrastructure devices, such as base stations, roadside units(RSUs), and servers.

Infrastructure Device—as used herein, may refer generally in the contextof V2X systems to certain devices in a V2X system that are not userdevices, and are not carried by traffic actors (i.e., pedestrians,vehicles, or other mobile users), but rather that facilitate userdevices' participation in the V2X network. Infrastructure devicesinclude base stations and roadside units (RSUs).

User Equipment (UE) (or “UE Device”) —any of various types of computersystems or devices that are mobile or portable and that perform wirelesscommunications. Examples of UE devices include mobile telephones orsmartphones (e.g., iPhone™. Android™-based phones), portable gamingdevices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™,iPhone™), laptops, wearable devices (e.g. smartwatch, smart glasses),PDAs, portable Internet devices, music players, data storage devices, orother handheld devices, etc. In general, the term “UE” or “UE device”can be broadly defined to encompass any electronic, computing, and/ortelecommunications device (or combination of devices) which is easilytransported by a user and capable of wireless communication.

Pedestrian UE (PUE) Device—a user equipment (UE) device as regarded inthe context of V2X systems that may be worn or carried by variouspersons, including not only pedestrians in the strict sense of personswalking near roads, but also certain other peripheral or minorparticipants, or potential participants, in a traffic environment. Theseinclude stationary persons, persons not on vehicles who may notnecessarily be near traffic or roads, persons jogging, running, skating,and so on, or persons on vehicles that may not substantially bolster theUE's power capabilities, such as bicycles, scooters, or certain motorvehicles.

Base Station—The term “Base Station” has the full breadth of itsordinary meaning, and at least includes a wireless communication stationinstalled at a fixed location and used to communicate as part of awireless telephone system or radio system.

Processing Element (or Processor) —refers to various elements orcombinations of elements that are capable of performing a function in adevice, such as a user equipment or a cellular network device.Processing elements include, for example, processors and associatedmemory, portions or circuits of individual processor cores, entireprocessor cores, individual processors, circuits such as an ASIC(Application Specific Integrated Circuit), programmable hardwareelements such as a field programmable gate army (FPGA), as well as anyof various combinations of the above.

Channel—a medium used to convey information from a sender (transmitter)to a receiver. It should be noted that since characteristics of the term“channel” may differ according to different wireless protocols, the term“channel” as used herein may be considered as being used in a mannerthat is consistent with the standard of the type of device withreference to which the term is used. In some standards, channel widthsmay be variable (e.g., depending on device capability, band conditions,etc.). For example, LTE may support scalable channel bandwidths from 1.4MHz to 20 MHz. In contrast, WLAN channels may be 22 MHz wide whileBluetooth channels may be 1 Mhz wide. Other protocols and standards mayinclude different definitions of channels. Furthermore, some standardsmay define and use multiple types of channels, e.g., different channelsfor uplink or downlink and/or different channels for different uses suchas data, control information, etc.

Configured to—Various components may be described as “configured to”perform a task or tasks. In such contexts. “configured to” is a broadrecitation generally meaning “having structure that” performs the taskor tasks during operation. As such, the component can be configured toperform the task even when the component is not currently performingthat task (e.g., a set of electrical conductors may be configured toelectrically connect a module to another module, even when the twomodules are not connected). In some contexts, “configured to” may be abroad recitation of structure generally meaning “having circuitry that”performs the task or tasks during operation. As such, the component canbe configured to perform the task even when the component is notcurrently on. In general, the circuitry that forms the structurecorresponding to “configured to” may include hardware circuits.

Various components may be described as performing a task or tasks, forconvenience in the description. Such descriptions should be interpretedas including the phrase “configured to.” Reciting a component that isconfigured to perform one or more tasks is expressly intended not toinvoke 35 U.S.C. § 112, paragraph six, interpretation for thatcomponent.

FIG. 1—V2X Communication System

FIG. 1 illustrates an example vehicle-to-everything (V2X) communicationsystem, according to some embodiments. It is noted that the system ofFIG. 1 is merely one example of a possible system, and that features ofthis disclosure may be implemented in any of various systems, asdesired.

Vehicle-to-everything (V2X) communication systems may be characterizedas networks in which vehicles, UEs, and/or other devices and networkentities exchange communications in order to coordinate trafficactivity, among other possible purposes. V2X communications includecommunications conveyed between a vehicle (e.g., a wireless device orcommunication device constituting part of the vehicle, or contained inor otherwise carried along by the vehicle) and various other devices.V2X communications include vehicle-to-pedestrian (V2P),vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), andvehicle-to-vehicle (V2V) communications, as well as communicationsbetween vehicles and other possible network entities or devices. V2Xcommunications may also refer to communications between othernon-vehicle devices participating in a V2X network for the purpose ofsharing V2X-related information.

V2X communications may, for example, adhere to 3GPP Cellular V2X (C-V2X)specifications, or to one or more other or subsequent standards wherebyvehicles and other devices and network entities may communicate. V2Xcommunications may utilize both long-range (e.g., cellular)communications as well as short- to medium-range (e.g., non-cellular)communications. Cellular-capable V2X communications may be calledCellular V2X (C-V2X) communications. C-V2X systems may use variouscellular radio access technologies (RATs), such as 4G LTE or 5G NR RATs.Certain LTE standards usable in V2X systems may be called LTE-Vehicle(LTE-V) standards.

As shown, the example V2X system includes a number of user devices. Asused herein in the context of V2X systems, “user devices” may refergenerally to devices that are associated with mobile actors or trafficparticipants in the V2X system, i.e., mobile (able-to-move)communication devices such as vehicles and pedestrian user equipment(PUE) devices. User devices in the example V2X system include the PUEs104A and 104B and the vehicles 106A and 106B.

The vehicles 106 may constitute various types of vehicles. For example,the vehicle 106A may be a road vehicle or automobile, a mass transitvehicle, or another type of vehicle. The vehicles 106 may conductwireless communications by various means. For example, the vehicle 106Amay include communications equipment as part of the vehicle or housed inthe vehicle, or may communicate through a wireless communications devicecurrently contained within or otherwise carried along by the vehicle,such as a user equipment (UE) device (e.g., a smartphone or similardevice) carried or worn by a driver, passenger, or other person on boardthe vehicle, among other possibilities. For simplicity, the term“vehicle” as used herein may include the wireless communicationsequipment which represents the vehicle and conducts its communications.Thus, for example, when the vehicle 106A is said to conduct wirelesscommunications, it is understood that, more specifically, certainwireless communications equipment associated with and carried along bythe vehicle 106A is performing said wireless communications.

The pedestrian UEs (PUEs) 104 may constitute various types of userequipment (UE) devices, i.e., portable devices capable of wirelesscommunication, such as smartphones, smartwatches, etc., and may beassociated with various types of users. Thus, the PUEs 104 are UEs, andmay be referred to as UEs or UE devices. Note that although the UEs 104may be referred to as PUEs (pedestrian UEs), they may not necessarily becarried by persons who are actively walking near roads or streets. PUEsmay refer to UEs participating in a V2X system that are carried bystationary persons, by persons walking or running, or by persons onvehicles that may not substantially bolster the devices' powercapabilities, such as bicycles, scooters, or certain motor vehicles.Note also that not all UEs participating in a V2X system are necessarilyPUEs.

The user devices may be capable of communicating using multiple wirelesscommunication standards. For example, the UE 104A may be configured tocommunicate using a wireless networking (e.g., Wi-Fi) and/orpeer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fipeer-to-peer, etc.) in addition to at least one cellular communicationprotocol (e.g., GSM, UMTS, LTE, LTE-A, LTE-V, HSPA, 3GPP2 CDMA2000, 5GNR, etc.). The UE 104A may also or alternatively be configured tocommunicate using one or more global navigational satellite systems(GNSS, e.g., GPS or GLONASS), one or more mobile television broadcastingstandards (e.g., ATSC-M/H), and/or any other wireless communicationprotocol, if desired. Other combinations of wireless communicationstandards (including more than two wireless communication standards) arealso possible.

As shown, certain user devices may be able to conduct communicationswith one another directly, i.e., without an intermediary infrastructuredevice such as base station 102A or RSU 110A. As shown, vehicle 106A mayconduct V2X-related communications directly with vehicle 106B.Similarly, the vehicle 106B may conduct V2X-related communicationsdirectly with PUE 104B. Such peer-to-peer communications may utilize a“sidelink” interface such as the PC5 interface in the case of some LTEembodiments. In certain LTE embodiments, the PC5 interface supportsdirect cellular communication between user devices (e.g., betweenvehicles 106), while the Uu interface supports cellular communicationswith infrastructure devices such as base stations. The LTE PC5/Uuinterfaces are used only as an example, and PC5 as used herein mayrepresent various other possible wireless communications technologiesthat allow for direct sidelink communications between user devices,while Uu in turn may represent cellular communications conducted betweenuser devices and infrastructure devices, such as base stations. Forexample, NR V2X sidelink communication techniques can also be used toperform device-to-device communications, at least according to someembodiments. Note also that some user devices in a V2X system (e.g., PUE104A, as one possibility) may be unable to perform sidelinkcommunications, e.g., because they lack certain hardware necessary toperform such communications.

As shown, the example V2X system includes a number of infrastructuredevices in addition to the above-mentioned user devices. As used herein,“infrastructure devices” in the context of V2X systems refers to certaindevices in a V2X system which are not user devices, and are not carriedby traffic actors (i.e., pedestrians, vehicles, or other mobile users),but rather which facilitate user devices' participation in the V2Xnetwork. The infrastructure devices in the example V2X system includebase station 102A and roadside unit (RSU) 110A.

The base station (BS) 102A may be a base transceiver station (BTS) orcell site (a “cellular base station”), and may include hardware thatenables wireless communication with user devices, e.g., with the userdevices 104A and 106A.

The communication area (or coverage area) of the base station may bereferred to as a “cell” or “coverage”. The base station 102A and userdevices such as PUE 104A may be configured to communicate over thetransmission medium using any of various radio access technologies(RATs), also referred to as wireless communication technologies, ortelecommunication standards, such as GSM, UMTS, LTE, LTE-Advanced(LTE-A), LTE-Vehicle (LTE-V), HSPA, 3GPP2 CDMA2000, 5G NR, etc. Notethat if the base station 102A is implemented in the context of LTE, itmay alternately be referred to as an ‘eNodeB’, or eNB. Note that if thebase station 102A is implemented in the context of NR, it mayalternately be referred to as a ‘gNodeB’, or gNB.

As shown, the base station 102A may also be equipped to communicate witha network 100 (e.g., the V2X network, as well as a core network of acellular service provider, a telecommunication network such as a publicswitched telephone network (PSTN), and/or the Internet, among variouspossibilities). Thus, the base station 102A may facilitate communicationbetween user devices and/or between user devices and the network 100.The cellular base station 102A may provide user devices, such as UE104A, with various telecommunication capabilities, such as voice, SMSand/or data services. In particular, the base station 102A may provideconnected user devices, such as UE 104A and vehicle 106A, with access tothe V2X network.

Thus, while the base station 102A may act as a “serving cell” for userdevices 104A and 106A as illustrated in FIG. 1, the user devices 104Band 106B may be capable of communicating with the base station 102A. Theuser devices shown, i.e., user devices 104A, 104B, 106A, and 106B mayalso be capable of receiving signals from (and possibly withincommunication range of) one or more other cells (which might be providedby base stations 102B-N and/or any other base stations), which may bereferred to as “neighboring cells”. Such cells may also be capable offacilitating communication between user devices and/or between userdevices and the network 100. Such cells may include “macro” cells,“micro” cells, “pico” cells, and/or cells which provide any of variousother granularities of service area size. For example, base stations102A-B illustrated in FIG. 1 might be macro cells, while base station102N might be a micro cell. Other configurations are also possible.

Roadside unit (RSU) 110A constitutes another infrastructure deviceusable for providing certain user devices with access to the V2Xnetwork. RSU 110A may be one of various types of devices, such as a basestation, e.g., a transceiver station (BTS) or cell site (a “cellularbase station”), or another type of device that includes hardware thatenables wireless communication with user devices and facilitates theirparticipation in the V2X network.

RSU 110A may be configured to communicate using one or more wirelessnetworking communication protocols (e.g., Wi-Fi), cellular communicationprotocols (e.g., LTE. LTE-V, etc.), and/or other wireless communicationprotocols. In some embodiments, RSU 110A may be able to communicate withdevices using a “sidelink” technology such as LTE PC5 or NR V2X sidelinkcommunication techniques.

RSU 110A may communicate directly with user devices, such as thevehicles 106A and 106B as shown. RSU 110A may also communicate with thebase station 102A. In some cases, RSU 110A may provide certain userdevices, e.g., vehicle 106B, with access to the base station 102A. WhileRSU 110A is shown communicating with vehicles 106, it may also (orotherwise) be able to communicate with PUEs 104. Similarly, RSU 110A maynot necessarily forward user device communications to the base station102A. In some embodiments, the RSU 110A and may constitute a basestation itself, and/or may forward communications to the server 120.

The server 120 constitutes a network entity of the V2X system, as shown,and may be referred to as a cloud server. Base station 102A and/or RSU110A may relay certain V2X-related communications between the userdevices 104 and 106 and the server 120. The server 120 may be used toprocess certain information collected from multiple user devices, andmay administer V2X communications to the user devices in order tocoordinate traffic activity. In various other embodiments of V2Xsystems, various functions of the cloud server 120 may be performed byan infrastructure device such as the base station 102A or RSU 110A,performed by one or more user devices, and/or not performed at all.

FIG. 2—Communication Between a UE and Base Station

FIG. 2 illustrates a user equipment (UE) device 104 (e.g., one of thePUEs 104A or 104B in FIG. 1) in communication with a base station 102(e.g., the base station 102A in FIG. 1), according to some embodiments.The UE 104 may be a device with cellular communication capability suchas a mobile phone, a band-held device, a computer or a tablet, orvirtually any type of portable wireless device.

The UE 104 may include a processor (processing element) that isconfigured to execute program instructions stored in memory. The UE 104may perform any of the method embodiments described herein by executingsuch stored instructions. Alternatively, or in addition, the UE 104 mayinclude a programmable hardware element such as an FPGA(field-programmable gate array), an integrated circuit, and/or any ofvarious other possible hardware components that are configured toperform any of the method embodiments described herein, or any portionof any of the method embodiments described herein.

The UE 104 may include one or more antennas for communicating using oneor more wireless communication protocols or technologies. In someembodiments, the UE 104 may be configured to communicate using, forexample, CDMA2000 (1×RTT/1×EV-DO/HRPD/eHRPD) or LTE using a singleshared radio and/or GSM or LTE using the single shared radio. The sharedradio may couple to a single antenna, or may couple to multiple antennas(e.g., for MIMO) for performing wireless communications. In general, aradio may include any combination of a baseband processor, analog RFsignal processing circuitry (e.g., including filters, mixers,oscillators, amplifiers, etc.), or digital processing circuitry (e.g.,for digital modulation as well as other digital processing). Similarly,the radio may implement one or more receive and transmit chains usingthe aforementioned hardware. For example, the UE 104 may share one ormore parts of a receive and/or transmit chain between multiple wirelesscommunication technologies, such as those discussed above.

In some embodiments, the UE 104 may include separate transmit and/orreceive chains (e.g., including separate antennas and other radiocomponents) for each wireless communication protocol with which it isconfigured to communicate. As a further possibility, the UE 104 mayinclude one or more radios which are shared between multiple wirelesscommunication protocols, and one or more radios which are usedexclusively by a single wireless communication protocol. For example,the UE 104 might include a shared radio for communicating using eitherof LTE or 5G NR (or either of LTE or 1×RTT, or either of LTE or GSM,among various possibilities), and separate radios for communicatingusing each of Wi-Fi and Bluetooth. Other configurations are alsopossible.

FIG. 3—Block Diagram of a UE

FIG. 3 illustrates an example block diagram of a UE 104, according tosome embodiments. As shown, the UE 104 may include a system on chip(SOC) 300, which may include portions for various purposes. For example,as shown, the SOC 300 may include processor(s) 302 which may executeprogram instructions for the UE 104 and display circuitry 304 which mayperform graphics processing and provide display signals to the display360. The processor(s) 302 may also be coupled to memory management unit(MMU) 340, which may be configured to receive addresses from theprocessor(s) 302 and translate those addresses to locations in memory(e.g., memory 306, read only memory (ROM) 350, NAND flash memory 310)and/or to other circuits or devices, such as the display circuitry 304,wireless communication circuitry 330, connector I/F 320, and/or display360. The MMU 340 may be configured to perform memory protection and pagetable translation or set up. In some embodiments, the MMU 340 may beincluded as a portion of the processor(s) 302.

As shown, the SOC 300 may be coupled to various other circuits of the UE104. For example, the UE 104 may include various types of memory (e.g.,including NAND flash memory 310), a connector interface 320 (e.g., forcoupling to a computer system, dock, charging station, etc.), thedisplay 360, and wireless communication circuitry 330 (e.g., for LTE,LTE-A, LTE-V, 5G NR, CDMA2000, Bluetooth, Wi-Fi, GPS, etc.). The UE mayalso include at least one SIM device, and may include two SIM devices,each providing a respective international mobile subscriber identity(IMSI) and associated functionality.

As shown, the UE device 104 may include at least one antenna (andpossibly multiple antennas, e.g., for MIMO and/or for implementingdifferent wireless communication technologies, among variouspossibilities) for performing wireless communication with base stations,access points, and/or other devices. For example, the UE device 104 mayuse antenna 335 to perform the wireless communication.

The UE 104 may also include and/or be configured for use with one ormore user interface elements. The user interface elements may includeany of various elements, such as display 360 (which may be a touchscreendisplay), a keyboard (which may be a discrete keyboard or may beimplemented as part of a touchscreen display), a mouse, a microphoneand/or speakers, one or more cameras, one or more buttons, and/or any ofvarious other elements capable of providing information to a user and/orreceiving or interpreting user input.

As described herein, the UE 104 may include hardware and softwarecomponents for implementing features for performing V2X sidelinkcommunications, such as those described herein. The processor 302 of theUE device 104 may be configured to implement part or all of the methodsdescribed herein, e.g., by executing program instructions stored on amemory medium (e.g., a non-transitory computer-readable memory medium).In other embodiments, processor 302 may be configured as a programmablehardware element, such as an FPGA (Field Programmable Gate Array), or asan ASIC (Application Specific Integrated Circuit). Alternatively (or inaddition) the processor 302 of the UE device 104, in conjunction withone or more of the other components 300, 304, 306, 310, 320, 330, 335,340, 350, 360 may be configured to implement part or all of the featuresdescribed herein, such as the features described herein.

FIG. 4—Block Diagram of a Base Station

FIG. 4 illustrates an example block diagram of a base station 102 (e.g.,base station 102A in FIG. 1), according to some embodiments. It is notedthat the base station of FIG. 4 is merely one example of a possible basestation. As shown, the base station 102 may include processor(s) 404which may execute program instructions for the base station 102. Theprocessor(s) 404 may also be coupled to memory management unit (MMU)440, which may be configured to receive addresses from the processor(s)404 and translate those addresses to locations in memory (e.g., memory460 and read only memory (ROM) 450) or to other circuits or devices.

The base station 102 may include at least one network port 470. Thenetwork port 470 may be configured to couple to a telephone network andprovide a plurality of devices, such as UE devices 104, access to thetelephone network

The network port 470 (or an additional network port) may also oralternatively be configured to couple to a cellular network, e.g., acore network of a cellular service provider. The core network mayprovide mobility related services and/or other services to a pluralityof devices, such as UE devices 104. In some cases, the network port 470may couple to a telephone network via the core network, and/or the corenetwork may provide a telephone network (e.g., among other UE devicesserviced by the cellular service provider).

The base station 102 may include at least one antenna 434, and possiblymultiple antennas. The at least one antenna 434 may be configured tooperate as a wireless transceiver and may be further configured tocommunicate with UE devices 104 via radio 430. The antenna 434communicates with the radio 430 via communication chain 432.Communication chain 432 may be a receive chain, a transmit chain orboth. The radio 430 may be configured to communicate via variouswireless communication standards, including, but not limited to, LTE,LTE-A, LTE-V, GSM, UMTS, CDMA2000, 5G NR, Wi-Fi, etc.

The base station 102 may be configured to communicate wirelessly usingmultiple wireless communication standards. In some instances, the basestation 102 may include multiple radios, which may enable the basestation 102 to communicate according to multiple wireless communicationtechnologies. For example, as one possibility, the base station 102 mayinclude an LTE radio for performing communication according to LTE aswell as a Wi-Fi radio for performing communication according to Wi-Fi.In such a case, the base station 102 may be capable of operating as bothan LTE base station and a Wi-Fi access point. As another possibility,the base station 102 may include a multi-mode radio which is capable ofperforming communications according to any of multiple wirelesscommunication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE andUMTS, LTE and CDMA2000, UNITS and GSM, etc.).

As described further subsequently herein, the BS 102 may includehardware and software components for implementing or supportingimplementation of features described herein. The processor 404 of thebase station 102 may be configured to implement or supportimplementation of part or all of the methods described herein, e.g., byexecuting program instructions stored on a memory medium (e.g., anon-transitory computer-readable memory medium). Alternatively, theprocessor 404 may be configured as a programmable hardware element, suchas an FPGA (Field Programmable Gate Array), or as an ASIC (ApplicationSpecific Integrated Circuit), or a combination thereof. Alternatively(or in addition) the processor 404 of the BS 102, in conjunction withone or more of the other components 430, 432, 434, 440, 450, 460, 470may be configured to implement or support implementation of part or allof the features described herein.

V2X Sidelink Communication

In wireless communications, specifically cellular wirelesscommunications, sidelink communications represent a special kind ofcommunication mechanism between devices that is not carried through abase station, e.g., through eNB/gNB. In other words, the devicescommunicate with each other without that communication going through abase station. In one sense, the devices may be said to be communicatingwith each other directly. Accommodation of such communication, however,requires a new physical layer design.

Many recent studies have identified the need for technical solutions forsidelink design, e.g. a sidelink design in 5G-NR, to meet therequirements of advanced V2X services, including support of sidelinkunicast, sidelink groupcast and sidelink broadcast. A number of specificuse cases have been identified for advanced V2X services, such asvehicle platooning, extended sensors, advanced driving, and remotedriving.

In LTE V2X, broadcast sidelink communications are supported, in whichmaintenance of the sidelink connection is performed using keep-alivemessages communicated between upper layers (e.g., application layers,non-access stratum layers, etc.) of the wireless devices incommunication. NR V2X supports unicast and groupcast sidelinkcommunications, e.g., in addition to broadcast sidelink communications.

In order to support such V2X sidelink communications, a variety ofcommunication channels (e.g., control channels, data channels) may needto be provided. Accordingly, various possible techniques supporting V2Xsidelink communication, including a variety of possible V2X channeldesign features and considerations, are proposed herein. The techniquesmay include techniques for slot aggregation and selective prioritizationof communications over a physical sidelink feedback channel (PSFCH) andvarious other techniques.

According to some embodiments, the wireless device may be operating in amanner such that the wireless device performs resource selection for itsV2X sidelink transmissions, which may also be referred to as a “mode 2”wireless device. In such a scenario, it may be beneficial for thewireless device to consider the potential impact on its transmissions ofits own and/or other wireless devices' half-duplex limitations. Forexample, if the wireless device is unable to (or not configured to)transmit and receive simultaneously, scheduling a transmission duringthe same slot that the wireless device is scheduled to receive atransmission by another wireless device may result in the wirelessdevice being unable to receive the transmission. Similarly, if adestination wireless device is unable to (or not configured to) transmitand receive simultaneously, scheduling a transmission to the destinationwireless device during the same slot that the destination wirelessdevice is scheduled to perform a transmission may result in thedestination wireless device being unable to receive the transmission.Accordingly, at least in some embodiments, the wireless device may beconfigured to selectively prioritize particular transmissions and/orreceptions for instances where a scheduled transmission and a scheduledreception at least partially overlap in time.

Scheduling Overlap for PSFCH Messages

Transmission and reception of PSFCH messages may be scheduled to overlapin time in a variety of different circumstances. As a first example, awireless device may transmit a PSSCH message and configure a scheduledtime slot for receiving a corresponding first acknowledgment messageover a PSFCH. Additionally, the wireless device may receive sidelinkcontrol information (SCI) from a remote device over the PSSCH indicatinga time slot for transmitting a second acknowledgment message over thePSFCH. In some cases, the PSFCH resources corresponding to these twoPSFCH messages may appear in the same slot. In these cases, embodimentsherein present methods and devices for selecting which of the PSFCHmessage to transmit or receive, based on data priority and/or otherfactors.

As a second example, a wireless device may be scheduled tosimultaneously transmit multiple PSFCH messages, or it may be scheduledto simultaneously receive multiple PSFCH messages. In these embodiments,the wireless device may determine which PSFCH message is associated withthe highest priority data, and may prioritize this PSFCH message fortransmission and/or reception.

As a third example, a wireless device may receive SCI from multipledifferent wireless devices, and the associated PSFCH responses mayappear in the same slot. Alternatively, a wireless device may receivemultiple SC messages from a single remote device, and the associatedPSFCHs may appear in the same slot. In these embodiments, the wirelessdevice may select a number of PSFCH transmissions to perform based ondata priority.

In some embodiments, a scheduling conflict may occur between a sidelink(SL) feedback transmission or reception and an uplink (UL) transmission.Embodiments herein present methods and devices to selectively prioritizeparticular transmissions and/or receptions.

Acknowledgment and/or negative acknowledgment (ACK/NACK) messages sentover the PSFCH may have either a short PSFCH format or a long PSFCHformat, in various embodiments. In some embodiments, a sequence-basedshort PSFCH format may be used for sidelink ACK/NACK messaging, whereone or two symbols are used for the ACK/NACK message. Alternatively, along PSFCH format may be used where more than two symbols are used forthe ACK/NACK message, e.g., up to the size of an entire slot (e.g., upto 14 symbols for a 14-symbol slot structure). In either of the long orshort PSFCH formats, the ACK/NACK message may be repeated for eachsymbol to increase the likelihood of successful reception by thereceiving device.

In some embodiments, sidelink control information (SCI) may betransmitted over the PSCCH and a data payload may be transmitted overthe PSSCH. The SCI information may specify the resources to be used foran upcoming PSFCH ACK/NACK message associated with the data payload. Insome embodiments, the SCI may specify a particular time, frequencyand/or code resource. Typically, the PSFCH resources may be offset fromthe corresponding PSSCH by 2 or 3 slots (i.e., the PSFCH may bescheduled to occur 2 or 3 slots after the PSSCH).

Embodiments here present methods and devices to further enhance PSFCHcoverage for longer distances and poor radio conditions. For example, insome embodiments, long PSFCH format slot aggregation is utilized toincrease message fidelity. Some embodiments present prioritization rulesfor resolving scheduling conflicts between PSFCH transmission andreception in a long PSFCH format with slot aggregation. Some embodimentspresent prioritization rules for resolving scheduling conflicts betweenmultiple simultaneous PSFCH transmissions in a long PSFCH format withslot aggregation. Some embodiments present prioritization rules forresolving scheduling conflicts between multiple simultaneous PSFCHtransmissions in a long PSFCH format with slot aggregation and a shortPSFCH format. Some embodiments present prioritization rules forresolving scheduling conflicts between PSFCH transmissions in a longPSFCH format with slot aggregation and uplink transmissions.

PSFCH Slot Aggregation

In some embodiments, a wireless device may configure slot aggregationfor PSFCH feedback messaging. For example, each data packet transmittedover a PSSCH resource may have corresponding PSFCH resources scheduledin a plurality of consecutive time slots for ACK/NACK feedback, startingfrom a configured (or pre-configured) gap after the PSSCH time resource.As used herein, the term “resource” is intended to refer to one or bothof a frequency resource and/or a time resource dedicated fortransmission or reception of a particular message over a particularchannel, such as the PSSCH, PSCCH or PSFCH. As illustrated in FIG. 5A,six different PSCCH/PSSCH resources each have two corresponding PSFCHtime resources, corresponding to an aggregation level of N=2. Asillustrated, each PSCCH and PSSCH resource occupies a single time slotand a single sub-channel, whereas each PSFCH resource occupies a singletime slot and a single physical resource block (PRB). For example, thesub-channel and time slot resource 502 is utilized to transmit bothsidelink control information over the PSCCH and sidelink data over thePSSCH. The sidelink control information in the resource 502 schedulesthe resources 504 and 506 for sending acknowledgment messaging over thePSFCH corresponding to the sidelink data sent over the resource 502.

In some embodiments, as shown in FIG. 5B, frequency hopping may beemployed on the PSFCH repetition. For example, to achieve a frequencydiversity gain, the two aggregate time slots for PSFCH messaging may beconfigured on two different frequency resources. The PSFCH frequencyoffset may be part of a resource pool configuration orpre-configuration, in various embodiments.

In some embodiments, PSFCH slot aggregation may be configured using asidelink control information (SCI) indication. In some embodiments, theaggregation level (i.e., the number of PSFCH time slots for each PSSCHresource) may be indicated in SCI stage 2.

In some embodiments, the maximum number of aggregate PSFCH slots may beupper bounded by a resource pool (pre)configuration. For example, theresource pool may configure N=4 as the maximum PSFCH aggregation level,whereas a particular SCI indicator transmitted by a wireless device mayconfigure an actual aggregation level of 2. The wireless device maydetermine its desired aggregation level based on a variety of factors,such as current radio conditions, reference signal received power (RSRP)of a remote device, distance to a remote device, etc. The size of thestage 2 SCI indicator indicating the aggregation level may be equal tolog, N, in some embodiments. In various embodiments. PSFCH slotaggregation may be configured for either a PSFCH long format or a PSFCHshort format.

In some embodiments, as shown in FIG. 5C, the two aggregate PSFCHresources may be configured on either side of the frequency resourcepool utilized for the PSSCH and the PSCCH. Advantageously, thisconfiguration may result in a greater diversity gain for the PSFCHresources than for the configuration shown in FIGS. 5A and 5B.

Prioritization Between PSFCH Transmissions and Receptions

In some embodiments, methods and devices are described to performselective prioritization for PSFCH ACK/NACK messaging when scheduledPSFCH transmissions and receptions overlap in time. One example isillustrated in FIG. 6A, where a wireless device transmits messaging overthe PSCCH and the PSSCH in a first time slot (PSCCH/PSSCH transmission,Tx), and the wireless device receives messaging over the PSCCH and thePSSCH in a subsequent neighboring second time slot (PSCCH/PSSCHreception, Rx). In this example, and as shown in FIG. 6A, it may occurthat the PSCCH/PSSCH transmission and the PSCCH/PSSCH reception arescheduled for PSFCH feedback during the same time slots for receivingand transmitting HARQ feedback, respectively. If the wireless device isa half-duplex device, the wireless device may be unable tosimultaneously transmit and receive PSFCH messaging in the same slot. Toaddress these and other concerns, the priority of the data associatedwith the overlapping PSFCH feedback messages may be considered todetermine whether to transmit or receive ACK/NACK messaging during theoverlapped time slot(s). For example, the wireless device may determinewhether a first data packet transmitted over the PSSCH during the firsttime slot or a second data packet received over the PSSCH during thesecond time slot has a higher priority. As illustrated in FIG. 61, thewireless device may transmit or receive the PSFCH message correspondingto the higher priority PSSCH data packet.

In some embodiments, if both the first and second data packets have thesame priority, the wireless device may autonomously determine whichPSFCH message to perform. For example, in these circumstances, thewireless device may default to always transmit a PSFCH message, oralternatively to always receive a PSFCH message when their respectiveassociated data packets have the same priority.

In some embodiments, time sharing of PSFCH messaging may be performed inconjunction with slot aggregation for one or both of the Tx and/or RxPSFCH messages. In these embodiments, time sharing may be implemented toaccommodate both the Tx and Rx PSFCH messaging. For example, asillustrated in FIGS. 7A-B, if the aggregation level of the Tx PSFCHmessage and the Rx PSFCH message is 2, the wireless device may allocateone of the aggregate time slots for the Tx PSFCH message and the otherof the aggregate time slots for the Rx PSFCH message. In someembodiments, the PSFCH message corresponding to the earlier PSSCHmessage may be allocated the earlier time slot(s) of the aggregate timeslots. For example, as shown in FIG. 7B, the PSCCH/PSSCH message 1 istransmitted before the PSCCH/PSSCH message 2 is received. Accordingly,the PSFCH message corresponding to message 1 may be received in theearlier of the two aggregate time slots, while the PSFCH messagecorresponding to message 2 may be transmitted in the later of the twoaggregate time slots.

In some embodiments, if the PSFCH aggregation level is more than 2,uneven PSFCH slot allocation may be applied, depending on the quality ofservice requirements and/or priority levels of the data packetscorresponding to the two PSFCH messages. For example, as illustrated inFIGS. 8A-B, PSCCH/PSSCH message 1 is higher priority than PSCCH/PSSCHmessage 2, and the PSFCH message corresponding to the higher prioritydata may have more slots allocated than the PSFCH message correspondingto the lower priority data.

In some embodiments, if the difference in priority between two PSSCHdata packets is sufficiently large, the PSFCH messaging associated withthe high priority PSSCH data packet may be allocated the entirety of theaggregate time slots. For example, if the Tx data packet sent over thePSSCH has a priority that is greater than the Rx data packet receivedover the PSSCH by more than a threshold amount, the entirety of thescheduled PSFCH time slots may be allocated to the PSFCH messagecorresponding to the Tx data packet (or vice versa). In someembodiments, different types of data packets may be designated differentpriorities on a scale from 1 (highest priority) to 8 (lowest priority).A priority difference threshold may be set (as one example, the prioritydifference threshold may be set to 6). If one data priority is level 1(highest) and the other data priority is level 8 (lowest), the gapbetween these two priority levels is 7, which is larger than thepriority difference threshold. Alternatively, a priority threshold levelmay be set (e.g., 4), wherein if the data priority of PSSCH Tx is largerthan a threshold, and data priority of the PSSCH Rx is smaller than thethreshold, the entirety of the scheduled PSFCH time slots may beallocated to the PSFCH message corresponding to the Tx data packet (orvice versa).

In some embodiments, the distance between the transmitting and receivingwireless devices may also be considered in allocating aggregate timeslots for PSFCH messaging. In some embodiments, a gap symbol may beadded at the end of a time slot for PSFCH messaging.

While embodiments herein have been described in the context of a timeoverlap between a Tx PSFCH message and an Rx PSFCH message, similarprioritization rules may be applied to the case of time overlap betweenmultiple PSFCH Tx messages.

In some embodiments, two scheduled PSFCH messages may partially overlap.For example, as shown in FIG. 9A, the PSFCH message corresponding tomessage 1 may be a long format PSFCH message with an aggregation levelof two, and one of scheduled PSFCH Rx resources may partially overlapwith the PSFCH resource corresponding to message 2. The PSFCH messagecorresponding to message 2 may have a short PSFCH format including onlyone or two symbols (i.e., rather than occupying an entire slot).

In some embodiments, similar to the methods described in reference toFIGS. 6A-B, the priorities and/or quality of service (QoS) requirementsof message 1 and message 2 may be compared to determine which of thePSFCH messages to transmit or receive. Alternatively, as shown in FIG.9B, time sharing may be employed where the short format PSFCHtransmission is performed in the first of the two aggregate time slots,whereas the long format PSFCH reception is performed in the secondnon-time overlapped time slot.

In some embodiments, if the data priority of the PSSCH data packetcorresponding to the long format PSFCH message is much larger than thedata priority of the PSSCH data packet corresponding to the short formatPSFCH message (i.e., larger by more than a pre-determined threshold),all of the aggregate PSFCH time slots may be used for the long formatPSFCH message. Alternatively, a pre-determined priority threshold may beset whereby, if the data priority of the PSSCH data packet correspondingto the long format PSFCH message is larger than the threshold and thedata priority of the PSSCH data packet corresponding to the short formatPSFCH message is smaller than the threshold, all of the aggregate PSFCHtime slots may be used for the long format PSFCH message.

Additionally or alternatively, in some embodiments, the distance betweentransmitting and receiving wireless devices may also be considered inconfiguring the PSFCH slot aggregation. Similar prioritizations rule maybe applied for cases where multiple overlapping PSFCH transmissions arescheduled.

FIG. 10—Flowchart for Selective PSFCH Prioritization

FIG. 10 is a flowchart diagram illustrating example aspects of methodsand devices for performing selective PSFCH prioritization, at leastaccording to some embodiments. Aspects of the method of FIG. 10 may beimplemented by a wireless device, such as a PUE 104, vehicle 106, any ofvarious other possible wireless devices illustrated in various of theFigures herein, and/or more generally in conjunction with any of thecomputer circuitry, systems, devices, elements, or components shown inthe above Figures, among others, as desired. For example, a processor(e.g., a baseband processor and/or other hardware) installed within sucha device may be configured to cause the device to perform anycombination of the illustrated method elements and/or other methodelements.

In various embodiments, some of the elements of the methods shown may beperformed concurrently, in a different order than shown, may besubstituted for by other method elements, or may be omitted. Additionalelements may also be performed as desired. As shown, the method of FIG.10 may operate as follows.

At 1002, first control information is received through a sidelinkcontrol channel specifying one or more first time slots for the wirelessdevice to transmit a first acknowledgment message over a sidelinkfeedback channel. The first acknowledgment message is related to a firstdata packet received by the wireless device. In some embodiments, thesidelink feedback channel is PSFCH, the sidelink control channel is aPSCCH, and the first data packet is received over a PSSCH. The firstcontrol information and the first data packet may be received during asingle common subchannel and time slot, and the acknowledgment messagemay be used to indicate whether the first data packet was successfullyreceived.

At 1004, second control information is transmitted through the sidelinkcontrol channel specifying one or more second time slots for thewireless device to receive a second acknowledgment message over thesidelink feedback channel. The second acknowledgment message is relatedto a second data packet transmitted by the wireless device. For example,second acknowledgment message may indicate whether the second datapacket was successfully received by a second device. The second controlinformation and the second data packet may be transmitted during asingle common subchannel and time slot.

At 1006, it is determined that one or more of the first time slotscoincide with one or more of the second time slots. For example, atleast some of the first time slots may overlap with at least some of thesecond time slots. If the wireless device is a half-duplex device thatis not able to simultaneously receive and transmit messagessimultaneously, selective prioritization may be employed to determinewhich of the sidelink acknowledgment messages to transmit or receiveduring the overlapping time slots.

At 1008, it is determined whether the first data packet or the seconddata packet has a higher priority. For example, each of the first andsecond data packets may include a specified data priority level (e.g.,on a scale of 1 for highest priority to 8 for lowest priority, oranother type of priority scale may be used), and these priority levelsmay be compared.

Alternatively, in some embodiments, the format of the first and secondacknowledgment messages may be used to determine priority. For example,in some embodiments it may be determined that one of the first or secondacknowledgment messages is to be transmitted/received according to along PSFCH format and the other is to be received/transmitted accordingto a short PSFCH format. In these embodiments, the acknowledgmentmessage that is to be transmitted or received according to the shortPSFCH format may be prioritized during the overlapping time slot.

At 1010, at least a subset of the overlapping time slots are utilizedfor transmitting or receiving either the first or second acknowledgmentmessage, respectively, depending on whether the first or secondacknowledgment message is associated with a higher priority data packet.

For example, when it is determined that the first data packet has thehigher priority, the first acknowledgment message is transmitted duringa first subset of the first time slots that coincide with one or more ofthe second time slots, and the second acknowledgment message is notreceived during the first subset of the first time slots. Alternatively,when it is determined that the second data packet has the higherpriority, the second acknowledgment message is received during the firstsubset of the first time slots and the first acknowledgment message isnot transmitted during the first subset of the first time slots.

In some embodiments, one or both of the first time slots and the secondtime slots include an aggregate plurality of time slots. The firstsubset of the first time slots may include a first portion of theaggregate plurality of time slots, and the second acknowledgment messagemay be received during a second portion of the aggregate plurality oftime slots that is disjoint from the first portion. The first portionmay be selected to be larger than the second portion based at least inpart on the determination that the first data packet has the higherpriority.

In some embodiments, it may be determined that the first data packet isto be received before the second data packet is to be transmitted. Basedon this determination, the first portion of the aggregate plurality oftime slots may be selected to occur before the second portion of theaggregate plurality of time slots. Alternatively, it may be determinedthat the first data packet is to be received after the second datapacket is to be transmitted, and the first portion of the aggregateplurality of time slots may be selected to occur after the secondportion of the aggregate plurality of time slots based on thisdetermination.

In some embodiments, it may be determined that the first data packet andthe second data packet differ in priority by more than a predeterminedthreshold amount, and based on this determination, the first subset ofthe first time slots used for transmitting/receiving the higher priorityacknowledgment message may include all of the overlapping time slots.

In some embodiments, control information may be utilized to configureaggregate time slots for PSFCH feedback. For example, one or both of thefirst or second control information may include a sidelink controlinformation (SCI) stage 2 indication that specifics an aggregation levelfor transmitting or receiving acknowledgment messages over the sidelinkfeedback channel, where a number of time slots equal to the aggregationlevel are used for transmitting or receiving the acknowledgmentmessaging. In some embodiments, the control information may specifyfrequency hopping for the acknowledgment messaging, whereby theacknowledgment messaging is to be transmitted or received duringdifferent aggregate time slots over different frequency bands. In someembodiments, the frequency hopping may be configured such that one ofthe frequency bands used for feedback messaging is higher than afrequency band used to transmit or receive the control information,while another of the frequency bands used for feedback messaging islower than the frequency band used to transmit or receive the controlinformation. In other words, the physical sidelink control channel(PSCCH) and the physical sidelink shared channel (PSSCH) may utilize afirst frequency band, and the PSFCH may utilize at least two frequencybands on either side of the first frequency for different time slots ofthe two or more aggregate time slots. Advantageously, the frequencydiversity gain may be enhanced in these embodiments by increasing thedifference in frequency between two of the frequency bands used forsidelink feedback messaging (e.g., compared to utilizing two adjacentfrequency bands for sidelink feedback messaging).

FIG. 11—Flowchart for PSFCH and UL Transmission Prioritization

In some embodiments, a scheduled PSFCH message may overlap in time witha scheduled uplink transmission. In these cases, in some embodiments,uplink transmissions may be always prioritized. For example, thetime-overlapped PSFCH may be dropped or power restricted, whereasnon-time-overlapped PSFCH transmissions may be performed as normal withnormal transmit power. Alternatively, in some embodiments existing NRV2X prioritization rules may be reused for overlapping uplinktransmissions and PSFCH transmissions. For example, the higherprioritized data may be transmitted in the overlapping time slot.

FIG. 11 is a flowchart diagram illustrating example aspects of methodsand devices for performing selective prioritization between sidelinkfeedback messaging and uplink data transfers, at least according to someembodiments. Aspects of the method of FIG. 11 may be implemented by awireless device, such as a PUE 104, vehicle 106, any of various otherpossible wireless devices illustrated in various of the Figures herein,and/or more generally in conjunction with any of the computer circuitry,systems, devices, elements, or components shown in the above Figures,among others, as desired. For example, a processor (e.g., a basebandprocessor and/or other hardware) installed within such a device may beconfigured to cause the device to perform any combination of theillustrated method elements and/or other method elements.

In various embodiments, some of the elements of the methods shown may beperformed concurrently, in a different order than shown, may besubstituted for by other method elements, or may be omitted. Additionalelements may also be performed as desired. As shown, the method of FIG.11 may operate as follows.

At 1102, control information is received through a sidelink controlchannel. The control information specifies one or more first time slotsfor the wireless device to transmit a sidelink acknowledgment messageover a sidelink feedback channel, where the sidelink acknowledgmentmessage is related to a first data packet received by the wirelessdevice. The first data packet may be received during the same time andfrequency resource within which the control information is received. Thecontrol information may be received over a physical sidelink controlchannel (PSCCH), whereas the first data packet is received over aphysical sidelink shared channel (PSSCH).

In some embodiments, the control information is a sidelink controlinformation (SCI) stage 2 indication. The SCI stage 2 indication mayindicate an aggregation level of the plurality of time slots.

At 1104, a resource grant is received through a downlink controlchannel. The resource grant may be received over a physical downlinkcontrol channel (PDCCH). The resource grant specifies one or more secondtime slots for the wireless device to transmit an uplink transmission,such as a second data packet (i.e., an uplink data packet) or controlinformation (e.g., HARQ-ACK messaging, CSI reporting, etc.) over anuplink channel. The uplink channel may be a physical uplink sharedchannel (PUSCH) (e.g., for an uplink data packet) or a physical uplinkcontrol channel (e.g., for control information).

At 1106, it is determined that one or more of the first time slotscoincide with one or more of the second time slots. For example, atleast some of the first time slots may overlap with at least some of thesecond time slots. If the wireless device is not able to transmit twomessages simultaneously, selective prioritization may be employed todetermine which of the sidelink acknowledgment message or the uplinktransmission to transmit during the overlapping time slots.

At 1108, time slots are determined for transmitting the sidelinkacknowledgment message and/or the second data packet, and at 1110, oneor more messages are transmitted according to the determination made atstep 1108. Various methodologies may be employed for determining whichmessage(s) to transmit during the overlapping time slots, as detailedbelow.

As a first example, in some embodiments, the uplink transmission isprioritized by default over the sidelink acknowledgment messaging. Inother words, the second data packet is transmitted over the uplinkchannel during the first time slots that coincide with one or more ofthe second time slots, and the sidelink acknowledgment message is nottransmitted during the overlapping first time slots.

Alternatively, the wireless device may be equipped with dual radios suchthat the uplink transmission and the sidelink acknowledgment messagingmay both be transmitted during a single time slot. In these embodiments,it may be desirable to reduce a transmission power used for transmittingthe sidelink acknowledgment messaging, to reduce the likelihood ofcreating intermodulation issues between the uplink data transmission andthe sidelink acknowledgment transmission. In these embodiments, thewireless device may transmit the uplink transmission with a normaltransmission power over the uplink channel during the one or more firsttime slots that coincide with one or more of the second time slots, andthe wireless device may transmit the sidelink acknowledgment messagewith a reduced transmission power during the overlapping one or morefirst time slots. In some embodiments, the first time slots are anaggregate plurality of time slots, where only a subset of the first timeslots overlap with the second time slots. In these embodiments, thefirst time slots that do not overlap with the second time slots may beused to transmit the sidelink acknowledgment message with a normaltransmit power.

As a third possibility, in some embodiments it may be determined whetherthe sidelink data packet associated with the sidelink acknowledgmentmessage (called the “first data packet”) or the uplink transmission(called the “second data packet”) has a higher priority. In theseembodiments, the wireless device may transmit the higher prioritymessage during the overlapping time slots. For example, based on adetermination that the uplink transmission has the higher priority, theuplink transmission may be transmitted during a first subset of thefirst time slots that coincide with one or more of the second timeslots, and the sidelink acknowledgment message may not be transmittedduring the first subset of the first time slots. Alternatively, based ona determination that the sidelink data packet has the higher priority,the sidelink acknowledgment message may be transmitted over the uplinkchannel during the first subset of the first time slots, while theuplink transmission is not transmitted during the first subset of thefirst time slots.

In some embodiments, it may be determined that the sidelink data packetand the uplink transmission differ in priority by more than apredetermined threshold amount. Based on this determination, the firstsubset of the first time slots may be selected to include all of thefirst time slots that overlap with one or more of the second time slots.Alternatively, if the sidelink and uplink transmissions differ inpriority by less than the threshold amount, or if they have the samepriority, a subset of the overlapping time slots may be used fortransmitting the sidelink data packet, while the remaining overlappingtime slots are used for transmitting the uplink transmission.

For example, in some embodiments the first time slots include anaggregate plurality of time slots, where the first subset of the firsttime slots that overlap with the second time slots are a first portionof the aggregate plurality of time slots. When the first portion of theaggregate plurality of time slots are used to transmit the uplinktransmission and not the sidelink acknowledgment message, a secondportion of the aggregate plurality of time slots disjoint from the firstportion may be used to transmit the sidelink acknowledgment message.

In some embodiments, the sidelink acknowledgment message is transmittedover at least two different frequency bands for two or more of theaggregate time slots. In some embodiments, the control information isreceived in a first frequency band, and the sidelink acknowledgmentmessage is transmitted in both a second frequency band and a thirdfrequency band during two different respective time slots, where thefirst frequency band is in between the second and third frequency band.The second and third frequency bands may be used for transmittingsidelink feedback, messaging for different time slots of the two or moreaggregate time slots. Advantageously, the frequency diversity gain maybe enhanced in these embodiments by increasing the difference infrequency between two of the frequency bands used for sidelink feedbackmessaging (e.g., compared to utilizing two adjacent frequency bands forsidelink feedback messaging).

In the following further exemplary embodiments are provided.

One set of embodiments may include an apparatus, comprising: a processorconfigured to cause a wireless device to perform any or all parts of thepreceding examples.

A further exemplary embodiment may include a method, comprising:performing, by a wireless device, any or all parts of the precedingexamples.

Another exemplary embodiment may include a device, comprising: anantenna; a radio coupled to the antenna; and a processor operablycoupled to the radio, wherein the device is configured to implement anyor all parts of the preceding examples.

A further exemplary set of embodiments may include a non-transitorycomputer accessible memory medium comprising program instructions which,when executed at a device, cause the device to implement any or allparts of any of the preceding examples.

A still further exemplary set of embodiments may include a computerprogram comprising instructions for performing any or all parts of anyof the preceding examples.

Yet another exemplary set of embodiments may include an apparatuscomprising means for performing any or all of the elements of any of thepreceding examples.

Still another exemplary set of embodiments may include an apparatuscomprising a processor configured to cause a wireless device to performany or all of the elements of any of the preceding examples.

It is well understood that the use of personally identifiableinformation should follow privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining the privacy of users. In particular,personally identifiable information data should be managed and handledso as to minimize risks of unintentional or unauthorized access or use,and the nature of authorized use should be clearly indicated to users.

Embodiments of the present disclosure may be realized in any of variousforms. For example, some embodiments may be realized as acomputer-implemented method, a computer-readable memory medium, or acomputer system. Other embodiments may be realized using one or morecustom-designed hardware devices such as ASICs. Still other embodimentsmay be realized using one or more programmable hardware elements such asFPGAs.

In some embodiments, a non-transitory computer-readable memory mediummay be configured so that it stores program instructions and/or data,where the program instructions, if executed by a computer system, causethe computer system to perform a method, e.g., any of a methodembodiments described herein, or, any combination of the methodembodiments described herein, or, any subset of any of the methodembodiments described herein, or, any combination of such subsets.

In some embodiments, a device (e.g., a UE 104) may be configured toinclude a processor (or a set of processors) and a memory medium, wherethe memory medium stores program instructions, where the processor isconfigured to read and execute the program instructions from the memorymedium, where the program instructions are executable to implement anyof the various method embodiments described herein (or, any combinationof the method embodiments described herein, or, any subset of any of themethod embodiments described herein, or, any combination of suchsubsets). The device may be realized in any of various forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

What is claimed is:
 1. A baseband processor configured to performoperations comprising: receiving first control information through asidelink control channel, wherein the first control informationspecifics one or more first time slots for the wireless device totransmit a first acknowledgment message over a sidelink feedbackchannel, wherein the first acknowledgment message is related to a firstdata packet received by the wireless device; transmitting second controlinformation through the sidelink control channel, wherein the secondcontrol information specifies one or more second time slots for thewireless device to receive a second acknowledgment message over thesidelink feedback channel, wherein the second acknowledgment message isrelated to a second data packet transmitted by the wireless device;determining that one or more of the first time slots coincide with oneor more of the second time slots; determining whether the first datapacket or the second data packet has a higher priority; and based atleast in part on a determination that the first data packet has thehigher priority: transmitting the first acknowledgment message during afirst subset of the first time slots that coincide with one or more ofthe second time slots, wherein the second acknowledgment message is notreceived during the first subset of the first time slots.
 2. Theapparatus of claim 1, wherein the operations performed by the basebandprocessor further comprise: based at least in part on a determinationthat the second data packet has the higher priority: receiving thesecond acknowledgment message during the first subset of the first timeslots, wherein the first acknowledgment message is not transmittedduring the first subset of the first time slots.
 3. The apparatus ofclaim 2, wherein the operations performed by the baseband processorfurther comprise: determining that the first acknowledgment message isto be transmitted according to a long PSFCH format; determining that thesecond acknowledgment message is to be received according to a shortPSFCH format, wherein said receiving the second acknowledgment messageduring the first subset of the first time slots is performed furtherbased at least in part on the determination that the secondacknowledgment message is to be received according to the short PSFCHformat.
 4. The apparatus of claim 1, wherein the operations performed bythe baseband processor further comprise: determining that the firstacknowledgment message is to be transmitted according to a short PSFCHformat; determining that the second acknowledgment message is to bereceived according to a long PSFCH format, wherein said transmitting thefirst acknowledgment message during the first subset of the first timeslots is performed further based at least in pan on the determinationthat the first acknowledgment message is to be transmitted according tothe short PSFCH format.
 5. The apparatus of claim 1, wherein the firsttime slots and the second time slots each comprise an aggregateplurality of time slots, wherein the first subset of the first timeslots comprises a first portion of the aggregate plurality of timeslots, wherein the operations performed by the baseband processorfurther comprise: receiving the second acknowledgment message during asecond portion of the aggregate plurality of time slots, wherein thesecond portion is disjoint from the first portion.
 6. The apparatus ofclaim 5, wherein the operations performed by the baseband processorfurther comprise: selecting the first portion to be larger than thesecond portion based at least in part on the determination that thefirst data packet has the higher priority.
 7. The apparatus of claim 5,wherein the operations performed by the baseband processor furthercomprise: determining that the first data packet is to be receivedbefore the second data packet is to be transmitted; and based at leastin part on the determination that the first data packet is to bereceived before the second data packet is to be transmitted, selectingthe first portion of the aggregate plurality of time slots to occurbefore the second portion of the aggregate plurality of time slots. 8.The apparatus of claim 5, wherein the operations performed by thebaseband processor further comprise: determining that the first datapacket is to be received after the second data packet is to betransmitted; and based at least in part on the determination that thefirst data packet is to be received after the second data packet is tobe transmitted, selecting the first portion of the aggregate pluralityof time slots to occur after the second portion of the aggregateplurality of time slots.
 9. The apparatus of claim 1, wherein theoperations performed by the baseband processor further comprise:determining that the first data packet and the second data packet differin priority by more than a predetermined threshold amount, based atleast in part on the determination that the first data packet and thesecond data packet differ in priority by more than the predeterminedthreshold amount, selecting the first subset of the first time slots toinclude all of the first time slots.
 10. The apparatus of claim 1,wherein the one or more first time slots comprise a plurality ofaggregate time slots, and wherein the first control informationcomprises a sidelink control information (SCI) stage 2 indication. 11.The apparatus of claim 10, wherein the operations performed by thebaseband processor further comprise: transmitting the firstacknowledgment message over at least two different frequency bands fortwo or more of the aggregate time slots.
 12. The apparatus of claim 10,wherein the first control information is received in a first frequencyband, wherein the operations performed by the baseband processor furthercomprise: transmitting the first acknowledgment message in a secondfrequency band higher than the first frequency band during a firstaggregate time slot of the plurality of aggregate time slots; andtransmitting the first acknowledgment message in a third frequency bandlower than the first frequency band during a second aggregate time slotof the plurality of aggregate time slots.
 13. The apparatus of claim 1,wherein the one or more second time slots comprise a plurality ofaggregate time slots, and wherein the second control informationcomprises a sidelink control information (SCI) stage 2 indication. 14.The apparatus of claim 13, wherein the operations performed by thebaseband processor further comprise: receiving the first acknowledgmentmessage in a different frequency band for two or more of the aggregatetime slots.
 15. The apparatus of claim 14, wherein the second controlinformation is transmitted in a first frequency band, wherein theoperations performed by the baseband processor further comprise:receiving the second acknowledgment message in a second frequency bandhigher than the first frequency band during a first aggregate time slotof the plurality of aggregate time slots; and receiving the secondacknowledgment message in a third frequency band lower than the firstfrequency band during a second aggregate time slot of the plurality ofaggregate time slots.
 16. A wireless device, comprising: at least oneantenna for performing wireless communications; a radio coupled to theat least one antenna; and a processor coupled to the radio; wherein thewireless device is configured to: receive first control informationthrough a physical sidelink control channel (PSCCH), wherein the firstcontrol information specifies a first set of resources for the wirelessdevice to transmit a first acknowledgment message over a physicalsidelink feedback channel (PSFCH), wherein the first acknowledgmentmessage is related to a first data packet; transmit second controlinformation through the PSCCH, wherein the second control informationspecifies a second set of resources for the wireless device to receive asecond acknowledgment message over the PSFCH, wherein the secondacknowledgment message is related to a second data packet; determinethat the first set of resources at least partially overlaps in time withthe second set of resources; determine which of the first data packetand the second data packet has a higher priority; based at least in parton a determination that the second data packet has the higher priority:receive the second acknowledgment message during at least a first subsetof the first set of resources, wherein the first subset overlaps in timewith the second set of resources, wherein the first acknowledgmentmessage is not transmitted during the first subset of the first set ofresources.
 17. The wireless device of claim 16, wherein the wirelessdevice is further configured to: based at least in part on adetermination that the first data packet has the higher priority:transmit the first acknowledgment message during the first subset of thefirst set of resources, wherein the second acknowledgment message is notreceived during the first subset of the first set of resources.
 18. Thewireless device of claim 16, wherein the first set of resources and thesecond set of resources each comprise an aggregate plurality of timeslots, wherein the first subset of the first set of resources comprisesa first portion of the aggregate plurality of time slots, wherein theprocessor is further configured to cause the wireless device to: receivethe second acknowledgment message during a second portion of theaggregate plurality of time slots, wherein the second portion isdisjoint from the first portion; and select the first portion to belarger than the second portion based at least in part on thedetermination that the first data packet has the higher priority.
 19. Amethod performed by a wireless device, the method comprising: receivingfirst control information through a sidelink control channel, whereinthe first control information specifies one or more first time slots forthe wireless device to transmit a first acknowledgment message over asidelink feedback channel, wherein the first acknowledgment message isrelated to a first data packet received by the wireless device;transmitting second control information through the sidelink controlchannel, wherein the second control information specifies one or moresecond time slots for the wireless device to receive a secondacknowledgment message over the sidelink feedback channel, wherein thesecond acknowledgment message is related to a second data packettransmitted by the wireless device; determining that one or more of thefirst time slots coincide with one or more of the second time slots;determining that the first data packet has a higher priority than thesecond data packet; and transmitting the first acknowledgment messageduring a subset of the first time slots that coincide with one or moreof the second time slots, wherein the second acknowledgment message isnot received during the subset of the first time slots.
 20. The methodof claim 19, the method further comprising: receiving third controlinformation through the sidelink control channel, wherein the thirdcontrol information specifies one or more third time slots for thewireless device to transmit a third acknowledgment message over asidelink feedback channel, wherein the third acknowledgment message isrelated to a third data packet received by the wireless device;transmitting fourth control information through the sidelink controlchannel, wherein the fourth control information specifies one or morefourth time slots for the wireless device to receive a fourthacknowledgment message over the sidelink feedback channel, wherein thefourth acknowledgment message is related to a fourth data packettransmitted by the wireless device; determining that one or more of thethird time slots coincide with one or more of the fourth time slots;determining that the fourth data packet has a higher priority than thethird data packet; and receiving the fourth acknowledgment messageduring a subset of the third time slots that coincide with one or moreof the fourth time slots, wherein the third acknowledgment message isnot transmitted during the subset of the third time slots.